The tree sap that engulfed the termite at left and then hardened into amber also preserved the methane bubbling from its hind end. Termites and their wood-digesting gut microbes emit millions of tons of methane each year.

Fuel of the future or climate bomb? A clump of icelike methane hydrate melts at room temperature and sea-level pressure, releasing the ignitable gas inside. The stuff is stable only under the seafloor or under Arctic permafrost, where there are vast deposits.

The little flask holds as much methane as the big one—as a powder rather than a gas. The University of Liverpool researchers who made the powder, a form of methane hydrate, think it could become a convenient way to store and transport natural gas.

The blue lines on this 3-D map are shale-gas wells. Assembled from seismic data, the map helps scientists at Chesapeake Energy’s Oklahoma City headquarters choose the best spots to drill. A typical well plunges a mile and a half, then turns horizontal inside the shale.

Brittle shale expands and cracks when brought up in a drill core from thousands of feet below. This sample is about two inches across. The white specks are salt crystals—residue from the ancient sea where the shale formed. To fracture shale underground and collect the gas trapped in its pores, gas companies pump millions of gallons of fracking fluids down a well.

So much methane fizzes from Sherry Vargson’s tap that she can light it like a stove. The contamination began, she says, after Chesapeake Energy drilled on her Pennsylvania farm. The company denies responsibility. “I keep about three windows open year-round so we don’t blow up,” Vargson says.

Kristianstad uses biogas to generate electricity and heat and to fuel cars and municipal garbage trucks and buses. Its two refineries produce enough biofuel to replace 1.1 million gallons of gasoline each year.

When Kristianstad’s cavernous new biogas reactor is full, it contains 1.6 million gallons of sludge, much of it pig intestines from the region’s slaughterhouses. The propeller-like agitators stir the organic waste, making it easier for microbes to digest—and in the process produce methane.

The first clear ice of fall on an Alaskan lake captures methane that all summer long has bubbled from the bottom mud. In spring it will be released into the air. As permafrost melts, new lakes are forming all around the Arctic.